INL/EXT-13-29679
2011 Hyundai Sonata 4932 - Hybrid Electric Vehicle Battery Test Results
Tyler Gray
Matthew Shirk Jeffrey Wishart
July 2013
The Idaho National Laboratory is a U.S. Department of Energy National Laboratory
Operated by Battelle Energy Alliance
INL/EXT-13-29679
2011 Hyundai Sonata 4932 Hybrid Electric Vehicle Battery Test Results
Tyler Gray1 Matthew Shirk2 Jeffrey Wishart1
July 2013
Prepared for the U.S. Department of Energy
Assistant Secretary for Energy Efficiency and Renewable Energy Under DOE Idaho Operations Office
Contract DE-AC07-05ID14517
1 ECOtality North America 2 Idaho National Laboratory
DISCLAIMER This information was prepared as an account of work sponsored by an agency of the U.S. Government. Neither the U.S. Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness, of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. References herein to any specific commercial product, process, or service by trade name, trade mark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the U.S. Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the U.S. Government or any agency thereof.
iii
Abstract The U.S. Department of Energy Advanced Vehicle Testing Activity Program consists of vehicle, battery, and infrastructure testing on advanced technology related to transportation. The activity includes tests on hybrid electric vehicles (HEVs), including testing the HEV batteries when both the vehicles and batteries are new and at the conclusion of 160,000 miles of on-road fleet testing. This report documents battery testing performed for the 2011 Hyundai Sonata Hybrid HEV (VIN KMHEC4A43BA004932). Battery testing was performed by the Electric Transportation Engineering Corporation dba ECOtality North America. The Idaho National Laboratory and ECOtality North America collaborate on the AVTA for the Vehicle Technologies Program of the DOE.
iv
Table of Contents
Abstract...................................................................................................................................... iii
List of Figures ............................................................................................................................ iv
List of Tables .............................................................................................................................. v
List of Acronyms ......................................................................................................................... v
1 Test Results ....................................................................................................................... 1 1.1 Static Capacity Test Results ..................................................................................... 1 1.2 Hybrid Pulse Power Characterization Test Results ................................................... 2 1.3 Acceleration Test Results ......................................................................................... 7 1.4 Fuel Economy Test Results ...................................................................................... 9 1.5 On-Road Test Results ............................................................................................ 12
2 Conclusion ....................................................................................................................... 12
Appendix A - Vehicle Specifications and Test Results Summary ............................................ A-1
List of Figures
Figure 1. Voltage versus energy discharged during the static capacity test ................................ 2
Figure 2. Ten-second charge pulse resistance versus energy discharged ................................. 3
Figure 3. Ten-second charge pulse power capability versus energy discharged ........................ 4
Figure 4. Ten-second discharge pulse resistance versus energy discharged ............................. 4
Figure 5. Ten-second discharge pulse power capability versus energy discharged .................... 5
Figure 6. Peak discharge and charge power versus energy discharged ..................................... 6
Figure 7. Useable energy versus power ..................................................................................... 7
Figure 8. Battery power versus time from acceleration testing ................................................... 8
Figure 9. Battery voltage versus time from acceleration testing .................................................. 8
Figure 10. Battery current versus time from acceleration testing ................................................ 9
Figure 11. Battery pack current, voltage, and vehicle speed for a UDDS dynamometer drive-
cycle. .................................................................................................................................10
Figure 12. Battery pack current, voltage, and vehicle speed for a HWFET dynamometer drive-
cycle. .................................................................................................................................11
Figure 13. Battery pack current, voltage, and vehicle speed for a US06 dynamometer drive-
cycle. .................................................................................................................................11
Figure 14. Monthly and cumulative fuel economy ......................................................................12
v
List of Tables
Table 1. Static Capacity test results ........................................................................................... 1
Table 2. HPPC test results ......................................................................................................... 3
Table 3. BOT and EOT acceleration test results ........................................................................ 7
Table 4. Battery performance results from the UDDS dynamometer drive-cycle testing ............10
List of Acronyms
Ah amp-hour
AVTA Advanced Vehicle Testing Activity
BOT beginning of test
C/3 the rate of battery discharge relative to one third its maximum capacity
DOD depth of discharge
DOE Department of Energy
EOT end of test
HEV hybrid electric vehicle
HPPC Hybrid Pulse Power Characterization
HWFET Highway Fuel Economy Test
INL Idaho National Laboratory
kW kilowatt
mi mile
MPH miles per hour
Ω ohm
s second
UDDS Urban Dynamometer Drive Schedule
US06 high speed/high load drive-cycle dynamometer test
V volt
VDC volt direct current
VIN vehicle identification number
Vpc volt per cell
Wh watt-hour
1
1 Test Results The U.S. Department of Energy (DOE) Advanced Vehicle Testing Activity (AVTA) Program consists of vehicle, battery, and infrastructure testing on advanced technology related to transportation. The activity includes tests on hybrid electric vehicles (HEVs), including testing the HEV batteries when both the vehicles and batteries are new (i.e., beginning-of-test or BOT) and at the conclusion of 160,000 miles3 of on-road fleet testing (i.e., end-of-test or EOT). This report provides test results for BOT and EOT battery testing conducted on a 2011 Hyundai Sonata HEV, number 4932 (full VIN: KMHEC4A43BA004932), from both laboratory and on-road test configurations. The battery laboratory test results include those from the static capacity test and the Hybrid Pulse Power Characterization (HPPC) Test.4 Vehicle test results include those from acceleration testing and fuel economy testing.5
The battery and vehicle testing was performed by the Electric Transportation Engineering Corporation dba ECOtality North America. The Idaho National Laboratory (INL) and ECOtality North America collaborate on the AVTA for the Vehicle Technologies Program of the DOE.
1.1 Static Capacity Test Results Results from the laboratory BOT and EOT Static Capacity tests are provided in Table 1.
Table 1. Static Capacity test results
Test Date Odometer
(mi) Rated Capacity
(Ah) Measured
Capacity (Ah) Measured
Energy (Wh) BOT June 17, 2011 4,123 5.30 5.26 1,395 EOT January 18, 2013 120,507 5.30 4.54 1,170 Difference — 116,384 — 0.72 (14%) 225 (16%)
Figure 1 shows battery voltage versus energy discharged. This graph illustrates voltage values during constant-current discharge versus cumulative energy discharged from the battery at a C/1 constant-current discharge rate at BOT and EOT.
3 The 2011 Hyundai Sonata VIN 4932 experienced malfunction in the drive train which caused testing to end before completing 160,000 miles. 4 Static capacity and HPPC test procedures are based on the FreedomCAR Battery Test Manual for Power-Assist Hybrid Electric Vehicles,
DOE/ID-11069, October 2003, Procedures 3.2 and 3.3, respectively. The measured capacity at BOT testing was used to determine the magnitude of current during all HPPC tests.
5 Acceleration testing and fuel economy testing procedures were performed in accordance with the Advanced Vehicle Testing Activity HEV America test procedures ETA-HTP02 and ETA-HTP03, respectively.
2
Figure 1. Voltage versus energy discharged during the static capacity test
1.2 Hybrid Pulse Power Characterization Test Results The HPPC test results are summarized below in Table 2. Figure 2 and Figure 4 illustrate the charge and discharge pulse resistance graphs of the battery, respectively. The internal resistance is depicted over a range of 10 to 90% depth of discharge (DOD), which is represented by the amount of energy discharged at each interval. Each curve represents the specified HPPC BOT or EOT resistance at the end of the 10-second pulse interval.
Figure 3 and Figure 5 illustrate the charge and discharge pulse power capability graphs of the battery, respectively. The power capability is depicted over a range of 10 to 90% DOD, which is represented by the amount of energy discharged at each interval. Each curve represents the calculated HPPC BOT or EOT available power capability at the end of the 10-second pulse interval at the cell voltage limits.
170
180
190
200
210
220
230
240
250
260
270
280
290
300
310
320
0 200 400 600 800 1000 1200 1400 1600
Vol
tage
(V)
Energy Discharged (Wh)
BOT EOT
3
Table 2. HPPC test results
10s Discharge Power
Capability (kW)
10s Charge Power
Capability (kW)
Maximum Cell
Voltage (V)
Minimum Cell Voltage
(V)
BOT 46.2 30.2 4.3 2.4 EOT 29.9 29.8 4.3 2.4 Difference 16.3 (35%) 0.40 (1.3%) 0 (0%) 0 (0%)
Figure 2. Ten-second charge pulse resistance versus energy discharged
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 200 400 600 800 1000 1200 1400
Cha
rge
Pulse
Res
ista
nce
(Ω)
Energy Discharged (Wh)
BOT
EOT
4
Figure 3. Ten-second charge pulse power capability versus energy discharged
Figure 4. Ten-second discharge pulse resistance versus energy discharged
0
10
20
30
40
50
60
70
0 200 400 600 800 1000 1200 1400
Pow
er (k
W)
Energy Discharged (Wh)
BOT
EOT
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 200 400 600 800 1000 1200 1400
Disc
harg
e Pu
lse
Res
ista
nce
(Ω)
Energy Discharged (Wh)
BOT EOT
5
Figure 5. Ten-second discharge pulse power capability versus energy discharged
Figure 6 is a plot of the BOT and EOT HPPC 10-second pulse charge and discharge power capability values of the battery as a function of energy discharged. The graph shows the power values over the range of energy discharged, with discharge power on the primary (left) axis and charge power on the secondary (right) axis. The DOE targets for a hybrid power-assist battery for discharge power (25 kW) and charge regenerative power (20 kW) are included for comparative purposes. The BOT pulse power values meet the DOE power targets (denoted by the black, horizontal dashed line in the figure) for the battery energy discharged range of 423 Wh to 1150 Wh. The EOT pulse power values meet the DOE power targets (denoted by the black, horizontal dashed line in the figure) for the battery energy discharged range of 440 Wh to 855 Wh.
0
10
20
30
40
50
60
70
80
90
0 200 400 600 800 1000 1200 1400
Pow
er (k
W)
Energy Discharged (Wh)
BOT EOT
6
Figure 6. Peak discharge and charge power versus energy discharged
Figure 7 is a plot of the BOT and EOT useable energy as a function of battery power. The x-axis indicates a desired discharge power level and the y-axis indicates the useable energy at that power. The dashed horizontal line shows the DOE minimum power-assist HEV energy target of 300 Wh. The dashed vertical line shows the DOE minimum power-assist discharge power target of 25 kW. A portion of the BOT useable energy curve of the Sonata battery falls above and to the right of the intersection of DOE energy and power targets. The maximum power that can be delivered while meeting the DOE energy target is 34.8 kW at 300 Wh. The maximum energy that can be delivered while meeting the DOE power target is 650 Wh at 26.8 kW. This indicates that at the time of BOT testing, the Sonata battery performance was above DOE targets. A portion of the EOT useable energy curve of the battery also falls above and to the right of the intersection of the DOE energy and power targets. The maximum power that can be delivered while meeting the DOE energy target is 27.5 kW at 300 Wh. The maximum energy that can be delivered while meeting the DOE power target is 430 Wh at 25 kW This indicates that at the time of EOT testing, the Sonata battery performance was above DOE targets.
0
10
20
30
40
50
60
70
0
10
20
30
40
50
60
70
80
90
0 200 400 600 800 1000 1200 1400
Cha
rge
Pow
er (k
W)
Disc
harg
e Po
wer
(kW
)
Energy Discharged (Wh)
EOT Dis Power BOT Dis Power BOT Ch Power EOT Ch Power Power Goal
7
Figure 7. Useable energy versus power
1.3 Acceleration Test Results BOT and EOT results from vehicle on-track acceleration tests are summarized in Table 3.
Table 3. BOT acceleration test results6
Average Discharge
Power Over 10s (kW)
Energy Discharged Over Test
(Wh)
Capacity Discharged Over Test
(Ah)
Peak Power Over Test
(kW)
Minimum Discharge
Pack Voltage (V)
Minimum Discharge
Cell Voltage (V)
BOT 26.5 194 0.75 43.3 246.5 3.424 Figure 8 shows battery power versus time during the one-mile acceleration test at BOT. This graph is the basis for power calculations over specified time or distance intervals and the cumulative discharged energy capacity during the duration of the test. At the beginning of the acceleration test, the power quickly increases from approximately 0 kW to a peak value. The power then remains relatively constant until battery or vehicle system dynamics, which may include battery control logic, cause a reverse in power direction to charge the battery.
Figure 9 shows the battery voltage versus time during the one-mile acceleration test at BOT and EOT. Values are analyzed to determine the minimum voltage allowed by the battery control module, if possible. Although the test may not yield a definitive minimum voltage value, it can provide an approximation for comparison to the HPPC analysis results. This graph also shows the impact of power electronics and battery controller on the voltage response.
6 Due to restrictions at the test track where acceleration tests were performed, the vehicle could not be accelerated for one full
mile.
0
100
200
300
400
500
600
700
800
900
1000
0 5 10 15 20 25 30 35 40 45
Use
able
Ene
rgy
(Wh)
Power (kW)
BOT
EOT
Power Goal
Energy Goal
8
Figure 8. Battery power versus time from acceleration testing
Figure 9. Battery voltage versus time from acceleration testing
-40
-30
-20
-10
0
10
20
30
40
50
0 5 10 15 20 25 Pow
er (k
W)
Time (s)
0
50
100
150
200
250
300
350
0 5 10 15 20 25
Volta
ge (V
)
Time (s)
9
Figure 10 shows battery current versus time during the one-mile acceleration test at BOT and EOT. This graph also is the basis for determining the discharged capacity during the test run. Lastly, the power results in Figure 8 can be obtained by simply multiplying the voltage values from Figure 9 by the current values in Figure 10.
Figure 10. Battery current versus time from acceleration testing
1.4 Fuel Economy Test Results Battery performance results from testing conducted on a chassis dynamometer (using the Urban Dynamometer Drive Schedule (UDDS), HWFET, and US067 at BOT and average fuel economy recorded while the vehicle was operating in an on-road fleet8, with approximately 36% city9 and 64% highway routes. Battery performance results are summarized in Table 4.
7 Urban Dynamometer Drive Schedule, HWFET, and US06 was performed as defined by the Environmental Protection Agency. The definitions
of each cycle can be found at http://www.epa.gov/nvfel/testing/dynamometer.htm#vehcycles 8 On-road fleet testing is performed by the ECOtality North America (in conjuncture with EZ-Messenger courier services). The vehicles are
driven a combination of city and highway routes by several different drivers to expedite the mileage accumulation required to reach EOT. 9 City routes are determined as trips with an average speed less than 42 mph.
-150
-100
-50
0
50
100
150
200
0 5 10 15 20 25
Cur
rent
(A)
Time (s)
10
Table 4. Battery performance results from the UDDS, Highway, and US06 dynamometer drive-cycle testing UDDS HWFET US06 Peak Discharge Power (kW): 39.3 36.0 43.5 Peak Regen Power (kW): 25.3 26.3 30.8 Measured Discharge Energy (kWh): 1.15 1.70 1.94 Measured Charge Energy (kWh): 1.03 2.05 2.06 Measured Discharge Capacity (Ah): 3.75 6.16 7.01 Measured Regen Capacity (Ah): 3.94 7.01 7.10 Minimum Pack Voltage (V): 252.7 260.3 256.4 Maximum Pack Voltage (V): 304.2 307.1 305.5 Discharge/Regen Ratio: 0.952 0.879 0.987
Figure 11, 12, and 13 show how the hybrid battery pack is utilized in comparison to vehicle speed for UDDS, HWFET, and US06 dynamometer drive-cycle testing. For each, the battery pack utilization is directly correlated to the driving style being performed in the drive-cycle. During the UDDS cycle, which simulates city driving with mildly aggressive accelerations and braking, the battery pack is in a perpetual state of transition between discharging and charging. During the HWFET cycle, which simulates highway driving where the vehicle is in nearly continuous motion, the battery pack shows a more steady-state use. During the US06 cycle, which is combined simulation of city and highway driving with a higher average speed, and aggressive accelerations and braking, the battery pack shows a combination of steady-state and transient use while at a higher average current input and output than in the other two cycles.
Figure 11. Battery pack current, voltage, and vehicle speed for a UDDS dynamometer drive-cycle
-300
-200
-100
0
100
200
300
0
50
100
150
200
250
300
350
0 200 400 600 800 1000 1200 1400 1600
Cur
rent
(A)
Spee
d (M
PH)
V
olta
ge (V
)
Time (s)
Vehicle Speed (MPH)
11
Figure 12. Battery pack current, voltage, and vehicle speed for a HWFET dynamometer drive-cycle
Figure 13. Battery pack current, voltage, and vehicle speed for a US06 dynamometer drive-cycle
-300
-200
-100
0
100
200
300
0
50
100
150
200
250
300
350
0 200 400 600 800 1000 1200 1400 1600 1800
Cur
rent
(A)
Spee
d (M
PH)
V
olta
ge (V
)
Time (s)
Vehicle Speed (MPH)
-300
-200
-100
0
100
200
300
0
50
100
150
200
250
300
350
0 200 400 600 800 1000 1200 1400
Cur
rent
(A)
Spee
d (M
PH)
V
olta
ge (V
)
Time (s)
Vehicle Speed (MPH) Battery Pack Voltage (V) Battery Pack Current (A)
12
1.5 On-Road Test Results Figure 14 presents the combined monthly fuel economy and cumulative fuel economy for Sonata HEV 4932 that underwent on-road fleet testing. The monthly fuel economy is derived from the amount of fuel consumed, based on fleet fueling records, and the distance traveled, based on vehicle odometer readings, for each vehicle within that month. The cumulative fuel economy is a running total of each month’s fuel consumption and distance traveled. The ending cumulative fuel economy over the course of fleet testing was 33.9 mpg. While the vehicle fuel economy cannot be directly correlated to operation of the battery pack with only these data, the vehicle fuel economy in Figure 14 is steady over the entirety of testing, even with battery degradation demonstrated by the EOT battery testing.
Figure 14. Monthly and cumulative fuel economy
2 Conclusion The Hyundai Sonata 4932 experienced a 14% decrease in battery capacity and stayed above DOE targets for all aspects of the HPPC test over the duration of 116,384 miles of fleet testing.
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
Mile
s per
Gal
lon
Monthly Fuel Economy
Cumulative Fuel Economy
A-1
Appendix A - Vehicle Specifications and Test Results Summary Vehicle Specifications Battery Specifications
Manufacturer: Hyundai Model: Sonata Year: 2011 Motor Power Ratinga: 34 kW VIN #: KMHEC4A43BA004932
Manufacturer: LG-Chem Battery Type: Lithium-ion Polymer Rated Capacity: 5.3 Ah Nominal Pack Voltage: 270 VDC Nominal Cell Voltage: 3.75 V Number of Cells: 72
Beginning-of-Test Vehicle Baseline Performance Test Resultsb
Acceleration Test Average Discharge Power Over 10 secondsc: 26.5 kW
Peak Discharge Power Over Test: 43.3 kW Energy Discharged Over Testd: 195 Wh
Capacity Discharged Over Testd: 0.75 Ah Minimum Discharge Pack Voltage: 246.5 VDC
Minimum Discharge Cell Voltage: 3.424 V Fuel Economy Chassis Dynamometer Testing
UDDS HWFET US06 Peak Discharge Power (kW): 39.3 36.0 43.5 Peak Regen Power (kW): 25.3 26.3 30.8 Measured Discharge Energy (kWh) 1.15 1.70 1.94 Measured Charge Energy (kWh) 1.03 2.05 2.06 Measured Discharge Capacity (Ah): 3.75 6.16 7.01 Measured Regen Capacity (Ah): 3.94 7.01 7.10 Minimum Pack Voltage (V) 252.7 260.3 256.4 Maximum Pack Voltage (V) 304.2 307.1 305.5 Discharge/Regen Ratioe: 0.952 0.879 0.987
Beginning-of-Test Battery Laboratory Test Results Hybrid Pulse Power Characterization Test Static Capacity Test
Peak Pulse Discharge Power @ 10 secondsf: 46.2 kW Peak Pulse Charge Power @ 10 secondsf: 30.2 kW Maximum Cell Charge Voltage: 4.3 V Minimum Cell Discharge Voltage: 2.4 V
Measured Average Capacity: 5.26 Ah Measured Average Energy Capacity:1,395 Wh Vehicle Odometer: 4,123 miles Date of Test: June 17, 2011
End-of-Test Battery Laboratory Test Results Hybrid Pulse Power Characterization Test Static Capacity Test
Peak Pulse Discharge Power @ 10 secondsf: 29.9 kW Peak Pulse Charge Power @ 10 secondsf: 29.8 kW Maximum Cell Charge Voltage: 4.3 V Minimum Cell Discharge Voltage: 2.4 V
Measured Average Capacity: 4.54 Ah Measured Average Energy Capacity:1,170 Wh Vehicle Odometer: 120,507 miles Date of Test: January 18, 2013
Degradation of Battery Over Test Periodg
Hybrid Pulse Power Characterization Test Static Capacity Test Peak Pulse Discharge Power @ 10 secondsf: 16.3 kW (35%) Peak Pulse Charge Power @ 10 secondsf: 0.4 kW (1.3%)
Measured Average Capacity: 0.72 Ah (14%) Measured Average Energy Capacity: 225 Wh (16%)
Notes: a. Motor power rating refers to the manufacturer’s peak power rating for the motor(s) supplying traction power. b. Vehicle test results are derived from baseline testing of Sonata VIN 4932. c. The peak power at a specified duration is the average power value over a specified interval. d. The capacity\energy value is defined as the net value over a 1-mile, full-throttle acceleration test. e. Ratio is calculated as the ratio of measured capacity discharge to measured capacity regenerated. The initial and final states
of charge are not specifically known, but are controlled by the battery management system and are within its normal range. f. Calculated value based on selected battery voltage limits and at 50% SOC of measured capacity at the time of BOT testing. g. All values are the degradation or difference in the battery from initial laboratory test to final laboratory test.
Recommended